I BEG YOU SOMEONE PLEASE HELP ME I AM GONNA CRY CUS OF THIS

I BEG YOU SOMEONE PLEASE HELP ME I AM GONNA CRY CUS OF THIS QUESTION

in this quetion : http://www.chegg.com/homework-help/12-pump-fig-p1124-scaled-size-provide-head-90-ft-flow-rate-1-chapter-11-problem-27p-solution-9780073529349-exc

HOW DID THE GET THE ROTATIONAL SPEED OF 19.3 FOR THE 12 IN PUMP ??!!! HELP PLEASEEE

Solution

Cool:)

Refer right top corner of the graph

The rotational speed is 1160 RPM

Just convert RPM (revolution per minute) to RPS (revolution per second) of mentioned speed

i.e., 1160/60 = 19.33 RPS